Impeller assembly for dishwashers



Oct. 27, 1953 L, JAMES ET AL 2,657,095

IMPELLER ASSEMBLY FOR DISHWASHERS Filed June 8, 1950 2 Sheets-Sheet l 653m nentors lW/IS 4411727615, and 8 04/0/76 4. James W i W Oct. 27, 1953L. A. JAMES ET AL 2,657,095

IMPELLER ASSEMBLY FOR DISHWASHERS Filed June 8, 1950 2 Sheets-Sheet .2

2 L V1 V 1 7 3 1/5 A. 1/0/7295, and J4 60 3 Duo/7e A /ames (IttomegsPatented Oct. 27, 1953 2,657,095 IMPELIJER ASSEMBLY FOR DISHWASHERSLBWiSfA. James (and Duane A. Independence, Kans.

J ames,

Application June 8, 1950, Serial No. 166,804

12 Claims; 1

invention relates to 'dishw'ash'ing'machines andimpeller assembliestherefor and more particularly to a dishwashenimpeller assemblyineluding a self-cleaning'filter and a rotary' or oseillatingballieagainst which washing liquid is dirEctedWith' considerable Velocity fordistribution in a sweepingmoveinent'over articles to be The objects ofthe present invention are to providea'dishwasher having an unitaryimpeller assembly in the washing compartment for moving liduid'from thebottoihof the compartment and delivering said liquid against a movingbaflle at considerable velocity for deflection onto articles t'obewashed; to provide a filter screen on the impeller unit for removingfood particles and the like from liquid drawn into the impeller unit; toprovide an impeller housing and related structure for directing deliveryof liquid whereby a portion thereof automatically cleans the paradesfrom the screen and prevents clogging thereof; to provide relatedcurvatures in the impllr baffle for effecting a sweeping action of theliquid over articles to be washed and minii'nizi'n'g noise andvibrationof operation; to prot 'i'de automatic apparatus for stopping delivery ofliquid from the impeller when the level of liquid in the washingcompartment is low and thereby reducing collection of mist or dropletson the Washed "articles as the liquid is being drained "from said"washing compartment; and

to provide a dishwashing machine and impeller "as's'efnbl'y'th'reforwhich are economical to manufacture and "efficient in operation forwashing and rinsing "dishes and the like and reducing the formationoi-uroplets thereon.

In accomplishing these and other objects of the present invention,we-have: provided" improved details or structure, the preferred forms ofwhich are illustrated in "the accompanying "drawings,

wherein:

Fig. =1 is a perspectiv view 'of a dishwasher impeller assembly withportions broken away to better illustrate the structure thereof.

Fig. 2 is aside elevation of the impeller assembly with portions brokenaway at theendsthereof to better illustratethe mounting of the impeller}bailleand baflle drive.

Fig. 3 is 'a transverse sectional view through a1 portion of adishwasher with theimpeller assembly mounted therein.

Fig. "e-is anendelevation ofthe impeller asthe impeller assembly with thliquid delivery from the impeller closed.

Referring more in detail to the drawings:

I designates a portion of a dishwashing machine having a washingcompartment 2 formed by side walls 3, end walls 4, bottom wall 5 and acoverinot shown). Th bottom 5 is preferably cylindrical with the axisthereof longitudinally of the washing compartment, whereby said bottomforms a sump for liquid 6-. A drain I has communication as at 8 with thewashin compartment andis controlled by a suitable valve 9 forselectively draining wash or rinse liquid from the washing compartment.

An impeller assembly I0 is mounted in the washing compartment andsuitably drive n to deliver washing and/or rinse liquid at considerablevelocity onto articles H to be washed which are preferably supported ona suitable rack I 2 arranged in the 'washingcompartment and supported onthe walls thereof. The impeller assembly Ill preferably is soconstructed {to form a unit adapted to be mounted in the washingcompartment -2 and extend longitudinally thereof, said impeller assemblybeing substantially coextensive with the washing compartment withgaskets l3 and I4 between the ends of the impeller unit and the endwalls 4 of the washing compartment. The impeller unit In generallyconsists of an impeller l-5 rotatably-mounted in a housing lfisandarranged to deliver washing orrinsing liquid at considerablevelocity-through a longitudinal .openingor slot I! in said housing anddirecting said liquid against a movably mounted baffle it which deflectsthe liquid inra sheet which sweeps over and impingesagainst articles tobe washed. The housing 16- is provided with end members I 9 and 20having inwardlyextending bearing'bosses 2| and 22 provided with boresHand 24 respectively-for rotatabl-ymountingthe ends of the impellershafts-25. The end members [9 and 20-are also provided with inwardlyextending flanges .26 and Z'lsubstantially coaxial with thebores 23 and24.

A substantially cylindrical shell 28, preferably formed of thin'sheetmetal is suitably secured to and supported by the endmembers I 9 and251. The 'ends of the shell 28 are preferably sleevedoverthe flanges 26and 21 and secured theretor-byfastening devices such asscrews "29.'Thelshell 28is provided with an opening 30 for :entrance of liquidinto'theimpeller housing. The opening 30 preferably extendslongitudinally of the housing and is substantially diametricallyasoppositevtheslot l1. A-filter.=3I of fine mesh wire screen covers theopening and is suitably secured to the shell 28 at the side edges 32 and33 of the opening 33 whereby all liquid entering the impeller housingmust pass through the filter 3| said screen being at an angle to theperiphery of the shell 28 for facilitating cleaning, as later described.

The impeller i5 consists of a blade 34 preferably formed of a singlesheet of metal suitably secured to the impeller shaft 25. In thestructure illustrated, the blade 34 is provided with a plurality oflongitudinally spaced cuts extending across the axis and perpendicularthereto and alternate portions of the blade defined by the cuts pressedlaterally to form a bore 35 whereby the impeller may be sleeved on theshaft 25 and the alternate portions defined by the cuts arranged onopposite sides of said shaft, the impeller being located on the shaftbetween the bearing bosses 2| and 22 and suitably secured to said shaftas by welding or the like whereby said impeller blade will rotate withthe shaft. The blade 34 has oppositely directed portions which terminatein side edges 36 and 36 slightly spaced from the inner surface of theshell 28 to provide clearance therebetween. It is preferable that theouter portions 31 of the blade be bent toward the direction of rotationof the impeller, and that the blade have a longitudinal twist or spiralof 180 to substantially equalize the force exerted between the bladesand the liquid throughout the length of the impeller.

As illustrated in Fig. 3, the impeller unit is so arranged that whenmounted in the washing compartment of the dishwasher the opening 33 inthe shell 28 is positioned adjacent the bottom 5 and the slot I! whichextends longitudinally of the impeller and is substantially coextensivetherewith is positioned whereby liquid moved by the impeller will bedirected through the slot ll substantially tangentially of the bladeportion 3'! and vertically at approximately the longitudinal center ofthe washing compartment.

The end members l9 and 20 have portions 40 and 4| extending upwardly andlaterally of the axis of the impeller and have bearing bosses 42 and 43provided with aligned bores 44 and 45 rotatably mounting trunnions 46and 41 which are fixed to the ends of the baffle l8, whereby the bafilerotates on an axis substantially parallel with the axis of the impellershaft and in alignment with the stream of washing liquid delivered bythe impeller through the slot H. The bafile l6 preferably consists of athin, fiat, elongated strip of metal of such length that the ends extendbeyond the ends of the slot H, the side edges 46 of said baffie havingclearance with the shell 28. The bafile I8 is preferably provided with alongitudinal twist or spiral of substantially 180, the direction of thespiral being opposite to the direction of the spiral of the impellerblade 34.

The end member H! is preferably provided with an outwardly extendingperipheral flange 49 and mounted on said flange is a plate 50 whichcooperates with the end member to enclose a drive which rotates thebaffle IS, the plate 50 being provided with bores 5| and 52 throughwhich extend the impeller shaft 25 and trunnion 46 respectively.Suitable seal rings 53 and 54 are provided in the bore 5| and bore 23 toretain any necessary lubricants in the baflle drive. It is preferablethat the baiiie rotate at a much slower speed than the impeller and inthe same direction, and while various driving mechanisms may be used inthe illustrated form the outer end of the shaft 25 extends beyond thebore 5| and is adapted to be suitably connected and driven by a primemover for rotating the shaft 25, An eccentric 55 is fixed to the shaft25 between the end member l9 and the plate 50 and rotatably mounted onthe eccentric is a strap 56 having a detent 51 extending therefrom. Thestrap is shown as consisting of two arcuate members 58 and 59 engagingaround the eccentric and held thereon by a spring 55 extending aroundthe peripheries of said arcuate members. The spring effects resilientengagement of the arcuate members with the eccentric whereby rotation ofsaid eccentric holds the end of the detent in engagement with the teeth6| of a ratchet wheel 62 fixed on the trunnion 46. Rotation of theeccentric 55 moves the detent to turn the ratchet wheel by increments,said ratchet wheel being held against backward movement by means of aspring pawl 63 suitably secured to the end member I9 and having its endengaging in teeth 6| of said ratchet wheel.

It is preferable that screws or the like 64 retain the plate 56 on theend member l9 and that the shanks of said screws extend outwardlythrough suitable openings in the end wall 4 of the washing compartmentfor mounting the impelier unit in said compartment in the position shownin Fig. 3. With the impeller unit arranged in this manner in the washingcompartment a pipe 65 connected to a suitable source of Washing andrinse liquid, for example a hot water tank in the water system of ahouse, extends through the bottom 5 of the washing compartment and intothe impeller housing adjacent the end member 20. A nozzle fitting 66 ismounted on the pipe 65 and so arranged as to direct liquid into theimpeller housing in a jet substantially parallel to the axis of theshaft 25.

The prime mover (not shown) is operated to drive the impeller [5 duringthe admission of liquid to the impeller housing and throws liquidupwardly around the interior of the shell l6 and delivers said liquid ina relatively flat stream or jet through the slot l1, substantiallytangentially to the arc of rotation of the impeller blade portion 31. Asthe impeller is rotated, the eccentric 55 is also rotated to move thedetent 51, thereby rotating the ratchet wheel 62 by increments. A streamof water discharged by the impeller through the slot I! strikes the sidesurfaces of the baffle l8 and is deflected thereby in fiat, thin sheetsor jets having considerable velocity to impinge on the articles to bewashed. As the baffle is rotated, it presents a gradual changingangularity of the side faces relative to the stream of water deliveredby the impeller, and this gradual changing surface deflects the streamof water in a sheet which sweeps the entire washing compartment.

When sufficient liquid is admitted to the washing compartment the supplyis turned off and operation of the impeller unit continued for aconsiderable period of time to thoroughly wash the articles, the washliquid being drawn into the impeller housing through the filter 3| anddelivered through the slot ll. Movement of the liquid through the filter3| tends to carry food particles and the like and deposit same on thescreen filter, and if said particles are not removed said filter wouldsoon be clogged. Due to the particular location of the opening 3!! andfilter therein and the slot ll, a portion of the liquid moved by theimpeller is carried around inside of memories theshellsllezandtthrowmagainst thesinsldenot'the screen filter: 3.1.-passingzthrough.sameuandxcarrw ingsofl thescollectedizfood particles.Thisraction istfacilitated having": the; screen". i 3 .1 arranged at" anslight 1 angle vto"thetperipherv'otfthe: shell. with: the: lowerrportiom of their screen. having greater; spacingr from; these impellerblades: than the upper portions-1 as: illustratedtin Also the filtercleaning; action repeats itself; on each revolution ofthezimpeller:Floodxiparticlescthereby are: washed? front: their screen; and: settle;tow the bottom :.of the: washing-"compartmentwherertheyremaimduring;the-balancevofilthe'washingiaction.

After the: articles are washed for'ar suitable period-bi? time thevalve: 9 is actuated to drain thev liquidrfromtthe washingicompartment:After draining; ther wash liquidi from: the washing compartmenm rinsealiquid is: supplied through the nozzlerfittingt 66s: ands. the"impeller: unit? operat'edito :throw the rinsevliquidlthrongh the slotl'l and di'recti same against theside; :faces of 'the battle I8;whichdeflects 'the'rinse liquidfin'a sheetsweepingtheentirewashingscompartmentz After rinsing" the articles-= thevalve 9 is: again on eratedl'to drain 'the'rinse waterf'rom thewashingcompartment;

It 1 has: been found that as: lthel liquidiis: drained from. the"washing: compartment the liquid delivered by the impeller. graduallydecreases in quantity" and finallybecomes a fine mist which is depositedin droplets: on the articles inthe washing compartment? Whenthedroplets: dry there' are small spots on the articles; To eliminate=tliis=-condi 'tiona: valve in the form ofa'flat vane t l is hingediymounted "as: at Ga on the shell '1 28 at the side of "the slot-ll; saidvalvebeing of such sizetha-t when the "freeend thereof isswung toward"the=shell 28it e1rgages the upper'side edge orthe sl'ot I l andsubstantiallyclosessameto out off delivery I oflicluid" through the"slot" I T; The valve is" provided with an' ear-twwhich-ispivotalconnected to'oner end of a link 1 0, the'other end of said linkbeing pivotal-Hy connected as: at" H to'a float lever12 whicli ispivotallymounted; as at T3; on an can 1'4 mounted on and-extendinglaterally of-"the shellr nl A fioahmemb'er' I5-'T'is mountedon'tl'ielever l2 whereby wh'en the level of liquid raises-in thewashihg'chamber the fioat swings the lever 12 exerting force on-tlie'linlt 1 0 to sw-ing thevalve 61 to -open position which issubstantiallyvertical-1y; whereby said valve-forms an extension of th e"shell and ism substantially tangentlal"thereto. In open position thevalve engages a log Hi on the-end member l9 which servesas a limit tothee opening of the valve. When the: liquid Flowers-in the washingcompel-t:- ment, as: when it"isbeingrdrained; to a; mode termined:=1'vel .iatwhizch :thel impellenwill' 'tend' to deliver? mist"insteadrof'a: stream? of 'liquid; the float movesr. downwardly with"thedevel: oi? liquid and; swings: the valve-stat closedpositionpshuttin'g air the delivery of; the-mist from? the: impeller,thereby permitting thewet articlesin; the 'wa-sh ingzcompartmentto drainandndry normally; with substantially no: liquid spots-1 thereon.

The? relatedispirals -ofi the: impeller: bladezand ba-file and therelativemfast. rotation of' the pel-ler anmslow: rotationofithe bafiiedirect the liquid delivered lb'y" the: impelierins the? form" of a? jetthat moves longitudinally" of z the: washing compartment "and latdiil'erent'fanglesi determined by" the: spiral ofj the: baflie; .and:rotation: of" the bailie causes: the: jetiatowsweep transverse-11y:otiithe washing: compartment, Therefore the: jet;. in cit feet; movesback; amdxfortluand; simultaneously advances-,ztransversely of. the:washing: compartment.:to completely. sweep the entireinteriozro! said.washing compartment Also the; spiral arr-'- rangement; of. theimpellerbladetenda to: equalize the. "force between. the. blade and l theliquidaxbeing moved; reducing vibration. andinoise in the opera:- tionof the unit.

Itais: believed, obvious that wehave providedla dishwasher and impellerunit: thereforwhich; is economical to manufactureand: efiicient in:operrationiofi delivering-a powerfulstream; of. liquid against articlesto be washed with a; self-cleaning filter for preventingareturningJoffood particles to the articles; said unit eliminating delivery ofmistz-tozthe articles; and thereby facilitating; drying; withoutliquidspots thereon.

What we claim and desire to secure byLetters Patentzis:

1:.. An" impeller unit for? dishwashing machines comprising; anelongated housing adapted" to;.be usedrinfixe'd horizontal position withthe lower portion below the level of liquid used in washing dishes, saidhousing: having openings substan=- tially oppositely arranged therein,one of? said openingsbeing in thealower portion of the.hous ing andforming a; liquid inlet andithe other'a liquid discharge opening; animpeller-shaft rotat a'bly-mounted in the housingandfextendinglongitudinally thereof; impeller blades fixed; on; the impeller shaft?and extending longitudinally thereof for; discharging liquid through thedis:- charge opening of the housing in response: to rotation 'of' theimpeller'shaft, an. elongated bafile spaced above and: aligned" withthe" discharge opening: of the housing and? movably' mounted thereonwhereby liquid: discharged through said openin is directediin a streamagainst-the bafile, and means formovingthe bafiieifor deflecting thestream of liquidand= providing: a. sweeping ac tion thereto:

2. An: impeller: unit for dishwashingmachines comprising, an elongatedhousingadapted to be used in fixedwhorizontal position with the lowerportion below: the: level of liquidused in washing dishes, saidhousingihaving'isubstantially oppo sl-tewopeningsi extending.longitudinally thereof, onerof'saidjopeningsbeing'in the lower portionof the housing and forming aaliquid inlet. and theJotherarliquiddischargeropening, an impeller shaftlIOtQtflblYIl'lOllIltfidgiIlthef hollsillg; impeller bladesfixedon-"theimpeller shaft and extending longitudinally thereof for dischargingliquid through the:dischargeopening of the housing in response torotation of: theimpeller shaft; an elongated baffie substantially?coextensive: with the impeller blades and parallel thereto, .means onthe: housing-:mormting the baiile "for rotation aboutlan axis-spacedabovea'and aligned with the dischargeopeningrof; therhousing wherebyliquid discharged, through; said opening; is directed in astreamaigainstl-the :baiile, andv means tforrmovin'g therhaflle': fordefiecting the "stream of liquid and providinga sweepingaction thereto.

3.. An impeller unit for: dishwashin wmachines comprising; an: elongatedsubstantially cylindrical housing adapted .to& be used'in fixedhorizontal position with the lower portion below the level ofliqui-dl-usedrin washing dishes; said housing having substantially.diametrically 'oppositeaopenings extending: longitudinally thereof,. oneof said openings being-in the lower portion of the housingi andwforminga; liquid: inlet the other: a liquid" discharge opening; an"; impellershafti rotatablyi mountedxin the housing:substantially on thelongitudinal; axis: thereof? impeller blades fixed on the impeller shaftand extending longitudinally thereof for discharging liquid through thedischarge opening of the housing in response to rotation of the impellershaft, said blades being in the form of a spiral about said shaft, an

elongated baffle substantially coextensive with the cal housing adaptedto be used in fixed horizontal position with the lower portion below thelevel of liquid used in washing dishes, said housing havingsubstantially diametrically opposite openings extending longitudinallythereof, one of said openings being in the lower portion of the hous ingand forming a liquid inlet and the other a liquid discharge opening, animpeller shaft rotatably mounted in the housing substantially on thelongitudinal axis thereof, impeller blades fixed on the impeller shaftand extending longitudinally thereof for discharging liquid through thedischarge opening of the housing in response to rotation of the impellershaft, an elongated bafiie spaced above and aligned with the dischargeopening of the housing and movably mounted thereon whereby liquiddischarged through said opening substantially tangentially f the housingis directed in a stream against the baffle, means for moving the bafflefor deflecting the stream of liquid and providing a sweeping actionthereto, a valve on the housing for opening and closin the dischargeopening thereof, and means responsive to the level of liquid around theexterior of the housing for operating said valve closing the dischargeopening in the housing when the level of liquid relative to the inletopening is inadequate to supply a suitable quantity of liquid to theimpeller.

5. An impeller unit for dishwashing machines comprising, an elongatedsubstantially cylindrical housing adapted to be used in fixed horizontalposition with the lower portion below the level of liquid used inwashing dishes, said housing having substantially diametrically oppositeopenings extending longitudinally thereof, one of said openings beingin'the lower portion of the housing and forming a liquid inlet and theother a liquid discharge opening, an impeller shaft rotatably mounted inthe housing substantially on the longitudinal axis thereof, impellerblades fixed on the impeller shaft and extending longitudinally thereoffor discharging liquid through the discharge opening of the housing inresponse to rotation of the impeller shaft, said blades being in theform of a spiral about said shaft, an elongated baffle substantiallycoextensive with the impeller blade and parallel thereto, means on thehousing mounting the baffle for rotation about an axis spaced above andaligned with the discharge opening of the housing whereby liquiddischarged through said opening substantially tangentially of thehousing is directed in a stream against the baffle, mean for rotatingthe baffle for deflecting the stream of liquid and providing a sweepingaction thereto, and a filter screen covering the liquid inlet opening ofthe housing, said screen being at an angle to the periphery of thehousing with the lower portion of said screen having the greater spacingfrom the impeller blades whereby a portion of liquid not dischargedthrough the discharge opening is carried around in the housing by theimpeller and directed across and through the screen for cleaning anymaterial therefrom.

6. An impeller unit for dishwashing machines comprising, an elongatedsubstantially cylindrical housing adapted to be used in a fixedhorizontal position with the lower portion below the level of liquidused for washing dishes, said housing having substantially diametricallyopposite openings extending longitudinally thereof, one of said openingsbeing in the lower portion of the housing and forming a liquid inlet'andthe other a liquid discharge opening, an impeller shaft rotatablymounted in the housing substantially on the longitudinal axis thereof,impeller blades fixed on the impeller shaft and extending longitudinallythereof for discharging liquid through the discharge opening of thehousing in response to rotation of the impeller shaft, an elongatedbaflle substantially coextensive with th impeller blades and parallelthereto, means on the housing mounting the baffle for rotation about anaxis spaced above and aligned with the discharge opening of the housingwhereby liquid discharged through said opening substantiallytangentially of the housing is directed in a stream against the baflie,means for moving the baffle for deflecting the stream of liquid andproviding a sweeping action thereto, a filter screen covering the liquidinlet opening of -the housing, said screen being at an angle to theperiphery of the housing whereby movement of liquid in the housing inresponse to rotation of the impeller discharges a portion of said liquidfrom the housing through the screen for cleaning any material therefrom,a valve hingedly mounted on the housing for opening and closing thedischarge opening thereof, and means responsive to level of liquidaround the exterior of the housing for operating said valve closing samewhen the level of liquid relative to the inlet opening is inadequate tosupply a suitable quantity of liquid to the impeller.

'7. An impeller unit for dishwashing machines comprising, an elongatedsubstantially cylindrical housing adatped to be used in fixed horizontalposition with the lower portion below the level of liquid used inwashing dishes, said housing having substantially diametrically oppositeopenings extending longitudinally thereof, one of said openings being inthe lower portion of the housing and forming a liquid inlet and theother a liquid discharge opening, an impeller shaft rotatably mounted inthe housing substantially on the longitudinal axis thereof, impellerblades fixed on the impeller shaft and extending longitudinally thereoffor discharging liquid through the discharge opening of the housing inresponse to rotation of the impeller shaft, an elongated baffiesubstantially coextensive with the impeller blades and parallel thereto,means on the housing mounting the baffle for rotation about an axisspaced above and aligned with the discharge opening of the housingwhereby liquid discharged through said opening substantiallytangentially of the housing is directed in a stream against the baflie,an eccentric fixed to the impeller shaft, a ratchet wheel fixed to thebaffle, and a pawl operated by the eccentric and engaging the ratchetwheel ridrimmed gi'n response td rotation I the impeller for rotating meane; by "mere" ments for deflecting the stream of liquid and havingsubstantially diametricallyopposite open ingsj extending longitudinallythereof, one 'f'said A,

openings being in the" lower portion of the hous; ingflmd form n "aliq'iiid'inl'et'. and the oth'e a liquid dischargeopening, anjimpellershaft'r tatably mounted in thehou'sing substantiallyion thefoligituclinal axis thereqr impeller blades; fixed on the im ener shaftand extending 1origi-" tudinally thereof for discharging liquid throughthe discharge opening of the housing in response to rotation of theimpeller shaft, said blades being in the form of a spiral about saidshaft, an elongated baille substantially coextensive with the impellerblades and parallel thereto, means on the housing mounting the bafflefor rotation about an axis spaced above and aligned with the dischargeopening of the housing whereby liquid discharged through said openingsubstantially tangentially of the housing is directed in a streamagainst the baffle, an eccentric fixed to the impeller shaft, a ratchetwheel fixed to the baffle, a pawl operated by the eccentric and engagingthe ratchet whee1 and operated in response to rotation of the impellerfor rotating the bafile by increments for deflecting the stream ofliquid and providing a sweeping action thereto, a filter screen coveringthe liquid inlet opening of the housing, said screen being at an angleto the periphery of the housing whereby movement of liquid in thehousing in response to rotation of the impeller discharges a portion ofsaid liquid from the housing through the screen for cleaning anymaterial therefrom, a valve hingedly mounted on the housing for openingand closing the discharge opening thereof, and means responsive to levelof liquid around the exterior of the housing for operating said valveclosing same when the level of liquid relative to the inlet opening isinadequate to supply a suitable quantity of liquid to the impeller.

9. An impeller unit for dishwashing machines comprising, an elongatedhousing adapted to be used in a fixed horizontal position with the lowerportion below the level of liquid used in washing dishes, said housinghaving openings substantially oppositely arranged therein, one of saidopenings being in the lower portion of the housing and forming a liquidinlet and the other a liquid discharge opening, an impeller shaftrotatably mounted on the housing and extending longitudinally thereof,impeller blades fixed on the impeller shaft and extending longitudinallythereof for discharging liquid through the discharge opening of thehousing in response to rotation of the impeller shaft, and a filterscreen covering the liquid inlet opening of the housing, said screenbeing substantially tangential with the periphery of the housingadjacent the upper portion of the inlet opening and having greaterspacing from the impeller blade at the lower portion of the inletopening whereby a portion of the liquid not discharged through thedischarge opening is carried around in the housing by the impeller anddirected across through the screen for dislodging any material adheringto the exterior thereof.

10. itinaimpell'erunit for dishwasing machines comprising, an elongatedsubstantially cylindricalhoii's'ifig adapted'to be used in fixedhorizontal positio withgtheolower*portion below the level of liquidusedin washingdishes, said housing having substantially diametricallyopposite openingsjfextending longitudinally :thereof, one of saidopenings being inthe lower portionof the housing and-forming aliquidinlet and theother a liquid discharge opening,tmrim p'eller shaft matatably mountediin the' housing. substantially on i the longitudirialaxiswthereof, impeller blades fixedon th'e timpeller, shaft "extendinglongitu-a dinallyi 'threof for i discharging 1 liquid through i thedis'charge'opening of the housing in response to rotation of =theimpellershaft, said bladesbeing in' thei form fofi'a spiral about said'shaft an elongated baiiie substantially coextensive'withthe impellerblades and parallel thereto, said baffle being on a spiral reversely tothe spiral of the impeller blades, means on the housing mounting thebaffle for rotation about an axis spaced above and aligned with thedischarge opening of the housing whereby liquid discharged through saidopening substantially tangentially of the housing is directed in astream against the baflie, means for rotating the baffle for deflectingthe stream of liquid and providing a sweeping action thereto, a valve onthe housing for opening and closing the discharge opening thereof, andmeans responsive to the level of liquid around the exterior of thehousing for operating said valve closing the discharge opening in thehousing when the level of liquid relative to the inlet opening isinadequate to supply a suitable quantity of liquid to the impeller.

11. An impeller unit for dishwashing machines comprising, an elongatedsubstantially cylindrical housing adapted to be used in fixed horizontalposition with the lower portion below the level of liquid used inwashing dishes, said housing having substantially diametrically oppositeopenings extending longitudinally thereof, one of said openings being inthe lower portion of the housing and forming a liquid inlet and theother a liquid discharge opening, an impeller shaft rotatably mounted inthe housing substantially on the longitudinal axis thereof, impellerblades fixed on the impeller shaft extending longitudinally thereof fordischarging liquid through the discharge opening of the housing inresponse to rotation of the impeller shaft, said blades being in theform of a spiral about said shaft, an elongated baflle substantiallycoextensive with the impeller blades and parallel thereto, said bafllebeing on a spiral reversely to the spiral of the impeller blades, meanson the housing mounting the baffle for rotation about an axis spacedabove and aligned with the discharge opening of the housing wherebyliquid discharged through said opening substantially tangentially of thehousing is directed in a stream against the baflie, means for rotatingthe bailie for deflecting the stream of liquid and providing a sweepingaction thereto, a flat valve hingedly mounted on the housing at one sideof the discharge opening thereof for opening and closing said dischargeopening, stop means for limiting opening of the valve whereby said valveforms a tangential extension of the housing and extends toward thebaffle, and means responsive to the level of liquid around the exteriorof the housing for operating said valve closing the discharge opening inthe housing when the level of liquid relative to the inlet opening isinade- 11 quate to supply a suitable quantity of liquid to the impeller.

12. An impeller unit for dishwashing machines comprising, anelongatedhousing adapted to be used in fixed horizontal position with the lowerportion below the level of liquid used in washing dishes, said housinghaving a liquid inlet opening in the lower portion thereof and a liquiddischarge opening in the portion above the level of liquid used inwashing dishes, means in the housing for discharging liquid through thedischarge opening, an elongated baffle spaced above and aligned with thedischarge opening of the housing, said baffle being spiraledlongitudinally thereof, means mounting the baflle for rotation about anaxis spaced above and aligned with the discharge opening whereby liquiddischarged through said opening is directed against the baflle, andmeans for rotating the baflle for defleeting the stream of liquid andproviding a sweeping action thereto.

Number Name Date 553,677 Hoyt Jan. 28, 1896 1,469,207 Blakeslee Oct. 2,1923 2,237,209 Arnold Apr. 1, 1941 2,257,929 Yochem Oct. 7, 19412,257,930 Yochem Oct. 7, 1941 2,274,024 Yochem Feb. 24, 1942 2,317,014Yochem Apr. 20, 1943

